Any way to make touch screen act like a touchpad?
So I'm looking all over my dash for a spot to mount a touch pad, and then it dawns on me that there's this huge 7" touch screen staring me in the face that's already beautifully mounted... Is there any way to switch the screen from acting like a regular touch screen to acting like touch pad, where the mouse arrow doesn't immediately jump to your finger, but instead just responds to the relative motions?
For digitizers and tablets I believe this is called switching from "Absolute Mode" to "Relative Mode".
A touch screen is great for clicking on big buttons to do things. But sometimes you need better precision like you'd get with a mouse or touchpad. Despite how tiny the screen is compared to a regular desktop, when I'm using a mouse I have no problem clicking on menus or small buttons that are practically impossible to hit with my finger on the touch screen.
I don't know how you'd trigger the switching between modes... There could be a button you click, or a place on the touchscreen you press and hold, or it could even just be related to which program you're using.
Has this been done? Anyone else think it would be useful? Any ideas how to pull it off?